Coleman’s Lead Down to 120 as Challenges Skyrocket

According to figures compiled by the Star Tribune, Norm Coleman now holds a lead of 120 votes over Al Franken. Coleman’s lead before the recount began had been 215 votes.

A majority of the state’s ballots — some 64 percent — have now been re-counted. The counties re-counted to date have been slightly redder than the state as a whole, favoring Coleman by an aggregate of about 1.6 points in the initial count. The difference has diminished, however, as more re-counted ballots roll in from Franken-friendly areas like Minneapolis.

Meanwhile, the number of ballot challenges — cases in which one or both candidates appeal an initial ruling my local elections judges — has increased significantly. Among ballots added to the Secretary of State’s totals since last evening, the Franken campaign has challenged 7.5 out of every 10,000 ballots, and the Coleman campaign 7.2 out of every 10,000. These figures are more than double the number of challenges on the first two days of the recount process.

On balance, Franken’s pace has slowed somewhat, while his rate of challenges has begun to match or slightly exceed that of the Coleman campaign. As such, Coleman should probably regarded as the slight favorite to retain his seat.

However, the uncertainty and ambiguity surrounding challenged ballots is very large, and tends to swamp everything else in the system. The fraction of challenged ballots can vary radically from county to county. We do not know whether one or another campaign is systematically making more frivolous challenges. In addition, we do not know what fraction of the challenges concern ballots that were initially ruled as legal (which the campaigns are now hoping to have discarded), versus ballots that initially were deemed to be overvotes or undervotes (which the campaigns are hoping to have counted). The first type of challenge will result in a temporary deduction to the opposing candidate’s total until the challenge is resolved, whereas the second type will have no immediate impact on the state’s reported totals.

Earlier today, the Franken campaign told the Huffington Post that it was within 100 votes based on a different standard of accounting for unresolved challenges. We have also heard, anecdotally, that Franken’s ballot judges have tended to be more experienced and better trained than Coleman’s ballot judges, perhaps suggesting that they will win a higher share of their challenges.

Nate Silver is the founder and editor in chief of FiveThirtyEight. @natesilver538